Aetiology of Exacerbations

Most COPD exacerbations are due to viral or bacterial infections of the respiratory tract, however in some cases they are caused by environmental pollution. Up to 30% have an unknown aetiology [5].

Table 1: Main known causes of COPD [7]

Other causes

While infection is by far the commonest case of an acute exacerbation of COPD it is important to consider other causes such as:

• Pneumothorax
• Pulmonary embolism
• Intra-abdominal pathology
• Cardiac failure
• Metabolic disturbance

Learning bite

Most COPD exacerbations are due to viral or bacterial infections of the respiratory tract, however, environmental pollution may also trigger an exacerbation. Up to 30% of exacerbations have an unknown trigger.